The present invention relates to a material for use in manufacturing bipolar semiconductor devices such as high voltage fast switching rectifiers and an all epitaxial method for making same.
The production of material for use in manufacturing semiconductor devices by epitaxial techniques and diffusion is well known. A process which employs an all epitaxial method is disclosed in copending application Ser. No. 08/015,384 filed Feb. 9, 1993 in the name of Joseph Chan et al. entitled Multilayer Epitaxial Structure and Method for Fabricating same. That application is assigned to the assignee hereof. Moreover, it is known to employ epitaxial techniques to form depletion layers with silicon/silicon-germanium interfaces under conditions which result in regions of misfit dislocations to control the switching speed of the power semiconductor devices. In this regard, the reader is referred to U.S. Pat. No. 5,097,308 and U.S. Pat. No. 5,102,810, both issued to Ali Salih and entitled method For Controlling The Switching Speed of Bipolar Power Devices. Both patents are owned by the assignee hereof.